An aerospace manufacturer recently turned to ESI whe one of their suppliers was having difficulty manufacturing a part, an aluminum air restrictor, to quality requirements and volume deadlines.

air restrictor for aerospace manufacturerHaving worked with ESI previously on other unconventional parts, the aerospace manufacturer felt confident that we would be able to approach the air restrictor with fresh eyes and ultimately provide an effective solution.

About the Part

An air restrictor is an integral part of a pitot-static system restrictor assembly. This assembly is part of an array used to determine an aircraft’s speed and altitude and display those values on the pilot’s instrumentation panel. A functioning pitot-static system restrictor is essential for the safe operation of an aircraft.

The Challenge

Producing an air restrictor of this type requires drilling a very small hole, 0.010 inches in diameter, through a relatively thick piece of 7075 aircraft-grade aluminum material. Due to the nature of the air restrictor’s role in the assembly’s precision, an extremely tight tolerance of .0005 inches in both diameter and location had to be maintained.

The Solution

ESI utilized our Yale University-educated manufacturing engineer, known for his out-of-the-box thinking and atypical approaches, to take charge of the project. Simply attempting to drill through the strong 7075 aluminum resulted in broken drill bits and holes far off specification, the same issues that the previous manufacturer was having when trying to manufacture the part.

After further experimentation, we were able to find a solution utilizing our Mori Seiki Multi-Axis Lathe and new self-centering high precision drills. We found that drilling the hole while machining the air restrictor in the lathe provided excellent results while eliminating costly secondary operations. Turning the lathe spindle at maximum RPMs in one direction, combined with using the live tooling capabilities of the lathe and turning the precision drill in the opposite direction of rotation, resulted in doubling the overall RPM affect.

When drilling such small diameters, 0.010” and below, within the specified tolerance and without any breakage of the drill bits, requires sustained RPMs that exceed most lathes’ capabilities. However, rotating the part in one direction and the drill in the opposite direction gave us just the solution we needed.

With an open mindset and the ability to think outside of the box, ESI not only supplied the aerospace manufacturer with high quality air restrictors, but did so 25% less expensively than the other manufacturer, Also, it was done in only three weeks’ time, less than one third of their original 10-week delivery estimate.

Contact us today to learn how we can deliver solutions for your next project.


Equipment UsedMori Seiki Multi- Axis Lathe
Overall Part Dimensions.187 Diameter x .250 Length
Tightest Tolerances+/- .0005” thru-hole
Material Used7075 Aluminum
Industry for UseAerospace - Helicopter
In-Process Testing/Inspection Performed Custom ultra-precision go/no-go pins
Delivery/Turnaround3 weeks